Pump construction

ABSTRACT

Apparatus for controlling the pressure applied to a liquid which is supplied to a nozzle wherein the pressurized liquid is mixed with a pressurized gas. Valve means controls the pressure applied to the liquid, and a variable chamber means is arranged to actuate the valve means. The variable chamber means contains work means responsive to changes in pressure in the gas whereby to actuate the valve means and thereby reduce the pressure on the liquid.

United States Patent 2,443,146 6/1948 Pules lnventor Casper M. GoffComstock Township, Kalamazoo County, Mich. (Rte. 1, Box 246, Galesburg,Mich. 49053) Appl. No. 775,310

Filed Nov. 13, 1968 Patented Jan. 5, 1971 PUMP CONSTRUCTION 6 Claims, 7Drawing Figs.

int. 605d 11/00 Field oiSearch 239/332,

References Cited UNITED STATES PATENTS 2,687,739 8/1954 Shelburne et al.239/334 3,146,786 9/1964 lshikawa 103/42X 3,207,378 9/1965 Trumbull eta1. 313 334x 3.341.128 9/1967 Magin etal 1239-304X 3,411,673 11/1968Mann .1. lO3/42X 3,433,240 3/1969 Lehmann 103/42X 3,474,965 10/ 1969Coleman Primary ExaminerLloyd L. King Attorneywoodhams, Blanchard andFlynn ABSTRACT: Apparatus for controlling the pressure applied to aliquid which is supplied to a nozzle wherein the pressurized liquid ismixed with a pressurized gas. Valve means controls the pressure appliedto the liquid, and a variable chamber means is arranged to actuate thevalve means. The variable chamber means contains work means responsiveto changes in pressure in the gas whereby to actuate the valve means andthereby reduce the pressure on the liquid.

not been entirely satisfactory.

,ru vii cons'rnu'crion FIELD or THE INVENTION This invention relates toa pump control structure and, 'rnore particularly, relates to valvestructure for activating and f it 3,552,417

deactivating a pumpfor supplying viscous liquid to a nozzle,

wherein the viscous liquid is mixed with a gas, such as air, and'wherein the operation of the valve structure is responsive to It hasbeen standard practice to heat the asphalt-used which is combined withsmall, stones to covera surface, such as a roof. .ln most instances,-the asphalt is heated in a large container an then carried in buckets orthe like to the surface where git is spread by some type of manuallyoperated applicator. The asphalt is usually applied to sheet material,such as tar paper (sometimes referred to as roof felt) which isplacedover the roof boards or other sublayer of the roof structure. Apparatushas been devised which eliminates the need for heated asphalt which mustbe carried in' buckets to'the surface being worked upon,- and suchapparatus is disclosed in the copending application of MyronsF. Goff,Ser. No. 650,794, filed July 3, l967. Moreover, it has been found thatthe cold asphalt material produces a Io'nger-Iastin'gand more weathercontrol system being responsive to but independent of the pump formoving the highly viscous liquid.

Other objects of this invention ,will become apparent upon reading thedescriptive material and examining the accompanying drawings, in which:

FIG, 1 is a schematic diagram of an apparatus including a pump embodyingthe invention.

FIG. 2 is a front view of the pumping device as used with a drum ofliquid.

FIG. 3 is a broken side view of the pumping device as seen from thecutting line III-III in FIG. 2. I

FIG. 4 is a sectional view taken-along the line IV-IV in FIG. 3

I FIG. 5 is a sectional view similar to FIG. 4 but with the pump valvesin different positions."

FIG. 6 is a side 'elevational vie view of the control valve mechanismand the control valve actuating unit.

FIG. 7 is a longitudinal sectional view of the valve actuating unitJ Forconvenience in description, the terms up," down," right and'left-.andwords of similar import will have I reference to the corresponding partsof the apparatus as apresistant surface which is farless likely to leakthan a hotasphalt roof. i v

Briefly, the cold asphalt. is pumped to a nozzle wherein the'coldasphaltbecomes entrained in a stream of air'and thereby sprayedontolthel surface being coveredf'llowever, many problems arose in thedevelopment-of a pump having sufficient power to. transfer the highlyviscous, cold asphalt liquid .from the storagercontainer to the nozzle.Moreover, it was necessary to adequately and accuratelycontrollthe pumpso that when the nozzle-was closed (by a control), thepressurizedviscou's asphalt liquid would notburst the conduitsinterconnecting the pump to the nozzle. While bursting could be avoidedby heavy-duty conduits, such conduits severely restricted the area whichcould be covered, due to their weight and stiffness- 4 One of severalattempts to solve the problem included the utilization of a pressurecontrol bypass valve located in the length of the conduit between thepump and the nozzle is pearing in the respective figures of thedrawings. The terms in, -out" and derivatives thereof will havereference to the geometric center of the device and designated partsthereof.

SUMMARY OF THE INVENTION The objects and purpose of the invention havebeen met by providing an apparatus capable of pumping a high volume ofrelatively cold and viscous liquid asphalt through a long con duit to anozzle where it is mixed with pressurized air, the pressure of .which isutilized to control the power means driving the pumping mechanism. Thissystem includes a lightweight, high-volume pump which has areciprocating piston driven by hydraulic fluid. A bypass valve isprovided in the hydraulic preferably at least 400 feet so that it canconveniently extend from a truck-up to a roof, ease of handling of theconduit is a necessity. However, the use of existing pump equipment hasVarious types of commercially available pumps were tried butthey-provedto be too heavy structurally and without adequately sensitive; pressurecutoff means. The viscousasphalt liquid is storedin portable containerssuch as SO-gallon drums. When one container becomes empty, it isnecessat ry to transfer'the pumps from the empty container to a fullference of the pump between containers extremely difficult and timeconsuming Accordingly, his a primary object of this invention to providea pump device which will move viscous liquid through a long conduit andwillfrespond by reducing its force upon: the liquid, in response to anabnormal increase in pressure of the liquid generated at a considerabledistance from the pump.

A further object of this invention has been the provision of a controlsystem, analogous to a bypass valve, for dumping the highly viscouspressurized liquid-back into a reservoir, the

DETAILED DESCRIPTION In the following descriptive material, the diagramof FIG. 1 will be discussed in general and then followed by a discussionof the individual components of the diagram to the extent required todisclose the invention.

. The apparatus lo utilized for pressurizing a viscous asphalt liquid 11and spraying same onto a surface of roof felt is comprised of a portableliquid container. 12 from which the liquid is removed by a liquid pump13 and urged through the conduit 14 to aflow control 16 and thence tothe'nozzle 17. The asphalt liquid may be mixed with other ingredientsand such is normally contemplated.

Hydraulic fluid 18 is drawn from a tank 19 by a hydraulic pump 21 drivenby a motor 22 whichsupplies the hydraulic fluid under pressure throughthe conduits 23 and 24 to the liquid pump 13. A bypass valve 26 in thehydraulic fluid line 27 diverts the flowof hydraulic fluid from the pumpmechanism 13 to the tank 19. The valve 26 (FIGS. 1 and 6) has a firstposition 28 directing the flow of fluid from the conduit 23 into theconduit 24 and a second position 29 diverting the flow of hydraulicfluid from the conduit 24 into the line 2 and back to the tank 19. I

The valve 26 is actuated by a variable chamber device 31 (FIGS. 6 and 7)which consists of a cylinder 32 having a piston 33 slidably disposedwithin the chamber'39 and a rod 34 connecting the piston 33 with thevalve element 35 in the bypass valve 26. A spring 40 normally biases thevalve 26 and the piston 33 into the positions thereof illustrated inFIGS. 1 and 7. That is, the valve element assumes the position 28 whichdirects the flow of hydraulic fluid through the conduit 24.

Air is pressurized by a conventional component, such as a compressor,generally indicated at 37 and is supplied through the conduit 38 to thechamber 39 of the variable chamber device 31. The air is supplied to theflow control 16 and the nozzle 17 through the conduit 36. A passageway41 of small cross section communicates through the walls of the cylinder32 between the opposite sides of the piston 33, where it is in itsnormal position of FIG. 7, so as to equalize the pressure on theopposite sides of the piston.

The conduits 14 and 36 may be in the order of 400 feet long so that mostof the apparatus can be located on the ground and the mixing valve orflow control 16 and nozzle 17 can be located with the operator on theroof ofa building. A pressure gauge 42 (FIG. 6) may be connected to theline 36 near the cylinder 32.

As illustrated in FIGS. 2 and 3, the pump 13 is secured to a frame 43and is reciprocated by the piston 47 of the hydraulic cylinder 46. Thatis, hydraulic fluid 18 is alternately supplied to opposite ends of thecylinder 46. A finger 48 is secured to L the piston rod 47 by an annularclamp 49, and the finger 48 extends radially therefrom. A pair of spacedlimit switches 51 and 52 are secured to the frame 43 and are disposed inthe path of the finger 48. The limit switches 51 and 52 are eitherelectrically or hydraulically connected to a conventional fourway valve45 for directing the hydraulic fluid alternately to the opposite ends ofthe cylinder 46 whereby the direction of hydraulic fluid flow to thecylinder 46 is automatically and intermittently reversed.

A pump cylinder 53 is secured to the lower end of the frame 43 and has acoaxial piston rod 54 secured to the lower end of the piston rod 47. Theexternal surface of the piston rod 54 and the internal surface 56 of thepump cylinder 53 define a pump chamber 57 having a volume such that asubstantial amount of liquid will flow upwardly through said chamber 57on the downward stroke of the piston 58 as well as on the upward strokethereof.

The piston 58 is slidably mounted on a bolt 59 which is connected to thelower end of the piston rod 54. The piston 58 has a plurality oflengthwise passageways 61 to provide communication between the oppositesides of the piston when it is in its raised position of FIG. 4. Thehead portion 63 of the bolt 59 has a seal 64 thereon which closes thelower ends of the passageways 61 when the piston is in its loweredposition of FIG. 5.

A ball check valve 66 is secured to the lower end of the pump cylinder53, and the ball element 67 is movable into and out of a positionwherein the opening 68 is completely blocked by the ball element 67 asillustrated in FIG. 4 to block the escape of asphalt when the piston 58is moved toward the ball check.

Conventional packing 68 is provided around the piston rod 54 adjacentthe upper end of the pump cylinder 53 to prevent the escape of viscousasphalt material around the extension member 54. The packing 69 issecured in place between a snap ring 71 and a packing gland 72.

The sideward nipple 73 adjacent the upper end of the pump cylinder 53defines the outlet ofthe pump chamber 57 and it is connected to theconduit 14 to supply viscous liquid asphalt to the control 16 and nozzle17.

The preferred embodiment of the valve 26 and the variable chamber device31 is illustrated in FIG. 6. The valve 26 is secured to a frame member76 by a plurality of bolts 77. The valve spring 36 encircles anextension of the rod 34 which is slidably received through a block 78 onthe frame 76 spaced from the valve 26. The valve element 35 is connectedto the rod 34 and is urged leftwardly (FIG. 6) by the spring 36, whichis compressed when the valve element is moved rightwardly by a movementof the piston 33 from its broken line position to its solid lineposition of FIG. 7. I

The device 31 (FIG. 7) has a pair of end caps 82 and 83 secured to theends of the cylinder 32 by a plurality of bolts 84. The passageway 41 isconnected to the chamber 39 through ports 86 and 87 in the wall of thecylinder 32, said ports being axially spaced a distance slightly greaterthan the thickness of the piston 33, as illustrated in FIG. 7. The port86 also communicates directly with the conduit 36 whereas the port 87 isspaced from the conduit 36 bythe length of passageway 41. The rod34,which is secured to the piston-33, extends through an opening 88 in theend cap '83 and is connected, as aforesaid, to the valve element 35, asillustrated in FIG. 6. An O-ring is providedbetween the periphery of therod 34 and the wall defining the opening 88 to prevent the escape of airfrom the chamber 39 ,o n.t h e right side of the piston 33 when thepiston is moved intothe po'sition illustrated in solid lines in FIG. 7.An O-ring 89 encircles the periphery of the piston 33 to provide a sealbetween the piston and the internal wall surface 90 of the cylinder 32.The O-ring 89 on the piston 33 remains between the ports 86 and 87regardless of the position of the piston. There is a slight spacebetween the peripheral wall of the piston 33 and the surface 90 ofcylinder 32.

The size of the opening 86 is such that there is a substantial pressuredrop as air flows from within the piston chamber 39, on the left side ofpiston 33, into the conduit 36. Such reduced pressure also appears onthe right side ofrthe piston 33 due to the passageway 41 and opening 87.Thisreduction in pressure is such that it compensates for the pressureexerted by the compressed spring 40 while the control device 16 isopened to permit the flow of air through the conduit 36 and nozzle 17.However, when the device 16 is closed, the pressure: will quicklyequalize on opposite sidesof the piston 33 thereby permitting the spring40 to move the piston into its broken line position of FIG. 7 where itblocks the port 86. However, some seepage occurs between the piston33-and the left end of the surface 90 so that the piston can move intothe broken line position of FIG. 7. r

OPERATION i. i

The operation of the device embodying the invention wil'l be apparent toskilled persons from the foregoing description, but a summary thereofwill be given hereinafter for convenience.

The pump 13 is set into a drum 12 so that the opening 68 at the bottomof the cylinder 53 is near the bottom of the drum which contains theviscous asphalt liquid 11 to be supplied through the device 16 and theconduit 14 to the nozzle 17. The piston rod 47 of the hydraulic cylinder46 and the piston rod 54 of the pump 13, being interconnected, arereciprocated by the alternating flow of hydraulic fluid into, and thenout of, the upper and lower ends of the cylinder 46. Accordingly, thepiston 58 is in the pump cylinder 53 will be moved with the rod 54. Whenthe piston 58 is moved upwardly (FIG. 5), the viscous asphalt liquid isdrawn from the container 12 through the opening 68 past the ball element67 into thepo rti'on of the chamber 57 below the piston 58, therebyfilling same. Simultaneously, the asphalt liquid within the portion ofthe chamber 57 above the piston 58 will be moved through the nipple 73and the conduit 14 to the nozzle 17. When the finger 48 actuates theswitch 52, the direction of movement of the piston rods 47 and 54 willbe reversed and the downward movement of the piston 58 will seat theball element 67 against the upper edge of the opening 68, therebytrapping the asphalt liquid in the lower end of the chamber 57. Thus,since the valve 58 is slidably mounted on the bolt 59, the piston 58will move upwardly on the bolt 59 so that the trapped liquid can movethrough the passageways 61 into the upper end of the chamber 57.However, since the cross-sectional area of the upper part of the chamber57 is less than the cross-sectional area of the chamber 57 below thepiston 58, due to the presence of the large piston rod 54, the asphaltliquid material will also be driven upwardly and out through the'opening73 as the piston 58 moves downwardly.

When the finger 48 actuates the switch 51, due to downward movement ofsaid rod 47, the direction of movement of the piston rods 47 and 54 willagain be reversed so that the piston 58 again moves upwardly, wherebythe piston 58 will slide downwardly to seal the lower ends of thepassageways 61 and the ball check 67 will close whereby to continue theupward flow of liquid through the chamber 57. Thus, it will be seen thata continuous flow of asphalt liquid is supplied through the conduit 14to the control,16 and nozzle 17 even though the piston 58 isreciprocated. I

Compressed air is supplied by the air compressor 37 to the control 16andnozzle 17 through the conduit 38, the variable chamber 39 of thedevice 31 and the conduit 36. When the control 16 permits the free flowof air and asphalt liquid to the nozzle 17 the force created by the airpressure on the left side of piston 33 is greater than the combinedforce created by the air pressure and the spring on the right side ofthe piston 33. Thus, the valve 26 and piston 33 are held in thepositions illustrated in H05. 1 and 7, wherein thevalve 26 directs theflow of hydraulic fluid into the conduit 24 andthenceto the pump 13. Asa result, hydraulic fluid will alternately cause the piston rods 47 andS4 of the pump mechanism 13 to reciprocate in the manner describedabove.

However, when the flow control 16 is closed and stops the flow ofpressurized air and asphalt liquid to the nozzle 16, the pressureincreases in the conduits l4 and 36. The pressure increase in conduit 36is promptly transferred through the passageway 41 and the'port 87 to thechamber 39 on the right side of the piston 33 (FIG. 7). The resultant,equalized pressure permits the spring 40 to move the piston 33leftwardly, thereby shiftingthe valve element 35so'that it assumesposition 29 (FIG. 1) wherein it diverts thehydraulic fluid to the line27 and reservoir 19. The pump mechanism 13 is thereby short circuited sothat no hydraulic fluid is supplied thereto to provide the pumpingaction of the piston 58 in the pump cylinder 53. Thus, theincreasedpressure in theconduit 14 is relieved and the conduitl4becornes relaxed. The conduit 36 still has pressurized air therein,but since air is compressible and light in weight, it creates no seriousproblem with respect to the handling of. the conduit.

The response of the device 31 is prompt and sensitive so that the valve26 is shifted quickly to short circuit the pump 13.- The response mustbe prompt because the pump l3:is so powerful that it could causeconsiderable damage if it continued to urge liquid into the conduit 14after the control 16 is closed.

it has been found that the device 31 operates effectively, as desired,regardless of wide variations in the pressure of the air supplied to thedevice through the conduit 38. For example, the pressure may vary from50 p.s.i. to 150 p.s.i. providing the various components are constructedto withstand l50 p.s.i. (which they can be) and the device 31 willperform without any adjustment to shift the valve 26, as discussedabove, when the control device 16 is closed.

In this embodiment, the opening 86 is made small because the pressure ofthe air supply is higher than normally required at the nozzle 17.However, by enlarging the opening 86 and reducing the opening 87. orpassageway 41', the same operating results could be achieved with thedevice 31 while providing an acceptable air pressure at the nozzle 17from a supply of,

about the same pressure. This suggests that the openings 86 and .87could be made adjustable-for a wider varietyof uses, if

desired.

Also, it will be seen that the switches 51 and 52 could be replaced by asingle electric switch which is closed during one stroke of the rod 47and openedduririg the reverse stroke.

Although a particular preferred embodiment of the invention has beendisclosed above for illustrative purposes, it will be understood thatvariations or modifications thereof, which lie within the scope of theappended claims, are fully contemplated.

I claim:

1. In a apparatus including hydraulic pump means for urging lating theflow of liquid and gas, the combination corn risin a source of hydraulicflur under pressure and thir con uit means connecting same to said pumpmeans; valve means in said third conduit means for diverting the flow ofhydraulic fluid to said pump means; and variable chamber meanscommunicating with said second conduit means, said variable chambermeans having movable wall means operably connected to said valve means'for operating same in response to a selected increase in the pressurewithin said second conduit means, whereby the pressure in said firstconduit means is reduced. 2. The apparatus defined in claim 1, whereinsaid gas is air and said liquid includes cold asphalt.

3. The apparatus defined in claimll, wherein said pump means comprisesfirst and second coaxial cylinders, first and second coaxial andinterconnected piston rods, and first and second pistons respectivelyconnected to said first and second rods within said first and secondcylinders, respectively, one of said cylinders being connected to saidthird conduit means and the other cylinder being connected to said firstconduit means whereby said one cylinder and its piston effectreciprocation of the other piston.

4. The apparatus defined in claim 3, wherein said variable chamber meanscomprises a third cylinder having a third piston slidably disposedtherein and defining said movable wall, said source of gas beingconnected to said third cylinder on one side of said third piston and tosaid control, said third piston being connected to. said valve means andsaid third cylinder being connected to atmosphere on the other side ofsaid third piston.

5. The apparatus defined in claim 4, wherein said third cylinder hasmeans defining a passageway communicating wit the interior of said thirdcylinder at spaced points; and including resilient means urging saidthird piston to remain in a first position between said points, whensaid liquid is flowing substantially normally, the strength of saidresilient means being such that a material increase in pressure of saidgas will overpower said resilient means and move said third piston intoa second position blocking said passageway at the point on said otherside of said third piston.

6. Apparatus for controlling the pressure applied to an incompressiblefluid supplied to a mixing chamber, wherein said incompressible fluid ismixed with a compressible fluid, comprising in combination:

first pressure-creating means pressurizing said compressible fluid andconnected in fluid circuit with said mixing chamber for supplyingcompressible fluid thereto; second pressure-creating means pressurizingsaid incompressible fluid and connected in fluid circuit with saidmixing chamber for supplying incompressible fluid thereto; 1

control means for regulating the flow of compressible and incompressiblefluids from said first and second pressurecreating means to said mixingchamber;

valve means connected in fluid circuit with said secondpressure-creating means for decreasing the pressure applied to saidincompressible fluid by said second pressurecreating'means; and

variable chamber means communicating with said compressible fluidcircuit, said variable chamber means having actuating means connected tosaid valve means for operating said valve means in response to aselected increase in the pressure of said gas, whereby the pressureapplied to said incompressible fluid is decreased.

1. In a apparatus including hydraulic pump means for urging a liquidthrough first conduit means and a source of gas under pressure connectedto a second conduit means, said first and second conduit means beingconnected to a control for regulating the flow of liquid and gas, thecombination comprising: a source of hydraulic fluid under pressure andthird conduit means connecting same to said pump means; valve means insaid third conduit means for diverting the flow of hydraulic fluid tosaid pump means; and variable chamber means communicating with saidsecond conduit means, said variable chamber means having movable wallmeans operably connected to said valve means for operating same inresponse to a selected increase in the pressure within said secondconduit means, whereby the pressure in said first conduit means isreduced.
 2. The apparatus defined in claim 1, wherein said gas is airand said liquid includes cold asphalt.
 3. The apparatus defined in claim1, wherein said pump means comprises first and second coaxial cylinders,first and second coaxial and interconnected piston rods, and first andsecond pistons respectively connected to said first and second rodswithin said first and second cylinders, respectively, one of saidcylinders being connected to said third conduit means and the othercylinder being connected to said first conduit means whereby said onecylinder and its piston effect reciprocation of the other piston.
 4. Theapparatus defined in claim 3, wherein said variable chamber meanscomprises a third cylinder having a third piston slidably disposedtherein and defining said movable wall, said source of gas beingconnected to said third cylinder on one side of said third piston and tosaid control, said third piston being connected to said valve means andsaid third cylinder being connected to atmosphere on the other side ofsaid third piston.
 5. The apparatus defined in claim 4, wherein saidthird cylinder has means defining a passageway communicating wit theinterior of said third cylinder at spaced points; and includingresilient means urging said third piston to remain in a first positionbetween said points, when said liquid is flowing substantially normally,the strength of said resilient means being such that a material increasein pressure of said gas will overpower said resilient means and movesaid third piston into a second position blocking said passageway at thepoint on said other side of said third piston.
 6. Apparatus forcontrolling the pressure applied to an incompressible fluid supplied toa mixing chamber, wherein said incompressible fluid is mixed with acompressible fluid, comprising in combination: first pressure-Creatingmeans pressurizing said compressible fluid and connected in fluidcircuit with said mixing chamber for supplying compressible fluidthereto; second pressure-creating means pressurizing said incompressiblefluid and connected in fluid circuit with said mixing chamber forsupplying incompressible fluid thereto; control means for regulating theflow of compressible and incompressible fluids from said first andsecond pressure-creating means to said mixing chamber; valve meansconnected in fluid circuit with said second pressure-creating means fordecreasing the pressure applied to said incompressible fluid by saidsecond pressure-creating means; and variable chamber means communicatingwith said compressible fluid circuit, said variable chamber means havingactuating means connected to said valve means for operating said valvemeans in response to a selected increase in the pressure of said gas,whereby the pressure applied to said incompressible fluid is decreased.